It is known to provide elevated or raised floors, also known as pedestal floors. Elevated flooring incorporates a number of height adjustable pedestals also known as pedestal jacks which are uniformly distributed over a sub-surface/sub-floor such as a concrete floor of a multi-storey building, a roof, terrace, or any other surface on top of which it is desired to locate an elevated floor. The pedestals cooperate in supporting floor panels, such as pavers, or other floor surfaces.
Pedestal jacks include a base, which includes a base plate on which the pedestal jack stands in use, and an annular cylindrical portion which extends upwards from the base and which is internally threaded. A connector element which is also annular and is internally and externally threaded is screwed into the base. A head portion incorporating a slope corrector also defines a depending annular portion which is externally threaded and is screwed into the connector. For a typical pedestal jack the three components may be screwed out to a height of approximately 150 mm. It is possible to increase the height of the unit by unscrewing the head and screwing in one or more extenders. Each extender will have a lower threaded portion which is configured to screw into the connector and an upper internally threaded annular portion into which the threaded portion of the head or another extender, may be screwed.
For safety reasons to ensure sufficient engagement of the various components due to their load bearing nature, and also to prevent the assembled units completely disengaging once installed, a safety catch is provided at the base of the externally threaded portions of the head, connector and extender, which co-operates with the internal threads of the component into which it is screwed to ensure that once assembled neither the head, extender nor connector can be disengaged from that, and ensures that at least three threads of each unit are engaged with that component. The safety catch is a pivoted wedge shaped block which defines a buttress-like face facing the start of the external thread.
In the internally threaded (female) components, the internal threads are discontinuous. The top three threads have relatively shallow ramped ends which allow the catch to deflect inwards whether being screwed clockwise or anti-clockwise. However the start of the lowermost thread defines a non-ramped buttress-like vertical face, which is substantially perpendicular to the internal circumference of the component adjacent a hole. When the components are screwed together the ramp of the safety catch deflects inwards and passes the buttress end. However when the components are subsequently unscrewed the face of the catch abuts the vertical buttress end of the thread preventing the components from being unscrewed further. The catch may be depressed by pushing a matchstick through the hole but this is fiddly and may damage the safety catch.
The components of pedestal jacks are relatively voluminous and thus can incur high shipping costs. Shipping costs could be reduced if the components of the pedestal jacks were screwed together for shipping. It is envisaged that a base connector and head unit could be screwed together, and a plurality of extenders could also be screwed together separately. However, the problem with this approach would be that it would be relatively fiddly and time consuming to disassemble the units at their destination due to the safety catches.
The present invention seeks to alleviate the above mentioned disadvantages.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.